(a) Field
The present invention relates to a machine tool provided with a tool post.
(b) Description of the Related Art
A CNC (Computerized Numerical Control) lathe provided with a guide bush holding a long workpiece gripped by a main spindle and provided with a pair of gang tool posts facing each other with the workpiece inbetween is conventionally known as a machine tool. Japanese Patent Application Publication No. 2005-88142 shows a lathe provided with a moving bed movable in a Y-direction perpendicular to an workpiece axial direction with respect to a supporting frame, a first tool post on which a plurality of tools are attached in the form of a comb in the Y-direction, and a second tool post on which a plurality of tools are attached in the form of a comb in the Y-direction. The first tool post is opposite the second tool post with the guide bush inbetween. The first tool post and the second tool post are independently movable in the workpiece axial direction and an X-direction perpendicular to the Y-direction. The moving bed is provided with first moving means for reciprocally moving the first tool post in the X-direction and second moving means for reciprocally moving the second tool post in the X-direction.
Simultaneous machining is enabled when the first moving means moves the first tool post in the X-direction toward the workpiece while the second moving means moves the second tool post in the X-direction toward the workpiece.